This invention relates to methods and systems for detecting an object in the path of a vehicle power window system utilizing acoustic signals.
Many vehicles today have electronically controlled windows and may even have electronically controlled sun/moon roofs. These systems provide the operator with ease in opening and closing the windows. However, if the operator is distracted while closing the window, it is possible for an object, such as an arm, hand or finger, to be caught between the window and the header, or seal, of the automotive window.
Techniques exist today to measure various characteristics of a motor associated with a power window system, such as motor current or torque, to assume an obstruction is in the way of the vehicle window. However, aging effects and/or external variables, such as temperature, friction from the seals, voltage levels, etc., result in these techniques being unreliable and unpredictable.
Thus, there exists a need for a reliable, yet inexpensive method and system for detecting an object caught in the path of a power window system.
An object caught in the path of a power window system is detected by sensing acoustic signals associated with the window as the window closes. The sensed acoustic signals are compared with a predetermined noise threshold, which can be either a predetermined reflected acoustic pattern associated with a predetermined reference acoustic signal or a previously sensed acoustic signal.
If a difference is detected, an object is assumed to be present in the path of the window. A control circuit acts accordingly to either stop or reverse direction of the motor closing the window.
These and other features of the present invention can be understood from the following specification and drawings.